Video: Plant Tissues and Tissue Systems

Vocabulary flashcards covering key terms from the Plant Tissues lecture notes (organs, tissues, cells, meristems, and woody growth).

Plant tissues

Groups of closely associated cells that perform related functions; organized into three tissue systems (dermal, ground, vascular).

Dermal tissue system

Outer protective covering; includes epidermis and periderm; protects and regulates exchange with the environment.

Epidermis

Outer protective layer in non-woody plants; may have root hairs and trichomes.

Periderm

Outer protective tissue in woody plants replacing the epidermis as stems thicken; includes cork cambium, cork, and cork parenchyma.

Cuticle

Waxy layer on the epidermis that reduces water loss.

Trichomes

Hairlike epidermal outgrowths aiding protection and reducing water loss.

Stomata

Pores in the leaf epidermis for gas exchange; surrounded by guard cells.

Guard cells

Specialized epidermal cells that regulate stomatal opening and closing.

Ground tissue system

Tissue system for storage, photosynthesis, and support; includes cortex and pith.

Parenchyma

Living, thin-walled cells with versatile roles in storage, photosynthesis, and secretion.

Collenchyma

Living cells with unevenly thickened primary walls; flexible support in growing parts.

Sclerenchyma

Rigid cells with thick secondary walls; provide structural support and durability.

Vascular tissue system

Long-distance transport system; includes xylem and phloem; provides support.

Xylem

Water-conducting tissue; contains tracheids and vessel elements; typically dead at maturity.

Tracheids

Long, tapered xylem cells with pits; contribute to water transport; usually dead at maturity.

Vessel elements

Water-conducting xylem cells forming vessels; connected end-to-end with perforation plates.

Phloem

Sugar-conducting tissue; alive at maturity; includes sieve-tube elements and companion cells.

Sieve-tube element

Living phloem cell that conducts sap; lacks a nucleus at maturity; connected by sieve plates.

Companion cell

Nonconducting phloem cell that supports sieve-tube elements; contains a nucleus.

Sieve plates

End walls between sieve-tube elements with pores enabling sap flow.

Stele

Central vascular cylinder of a root or stem; contains xylem, phloem, and associated tissues.

Endodermis

Innermost layer of cortex; boundary with vascular cylinder; regulates substance passage.

Pericycle

Outermost layer of the vascular cylinder; site of lateral root initiation.

Cortex

Ground tissue region between epidermis and endodermis in roots.

Root hair

Extension of a root epidermal cell increasing surface area for absorption.

Root cap

Protects the root tip and apical meristem as the root grows; secretes slime.

Zone of cell division

Region where the root apical meristem divides to form primary meristems.

Protoderm

Primary meristem that forms the epidermis.

Procambium

Primary meristem that forms xylem and phloem.

Ground meristem

Primary meristem that gives rise to cortex, pith, and ground tissue.

Apical meristem

Growth tissue at tips of roots and shoots; responsible for primary growth.

Shoot apical meristem

Dome-shaped mass at shoot tip; produces leaf primordia and internodes.

Leaf primordia

Early leaf formation along the shoot apical meristem.

Axillary bud

Bud in the leaf axil with potential to form a lateral shoot.

Terminal bud

Bud at shoot tip; elongates the young shoot; apical dominance inhibits axillary buds.

Lateral meristem

Meristematic tissue driving secondary growth; includes vascular cambium and cork cambium.

Vascular cambium

Lateral meristem that adds secondary xylem (inside) and secondary phloem (outside).

Cork cambium

Lateral meristem producing cork (and cork parenchyma); part of periderm.

Periderm

Outer protective tissue of woody plants formed by cork cambium, cork, and cork parenchyma.

Secondary growth

Girth growth produced by lateral meristems (vascular and cork cambium).

Sapwood

Young, outer wood that conducts water near the cambium.

Heartwood

Older central wood; non-conductive; provides structural support and often darker color.

Annual rings

Concentric wood rings indicating yearly growth; results from seasonal differences in cell size and wall thickness.

Springwood

Lighter, large-diameter xylem formed in spring when water is abundant.

Summerwood

Darker, thick-walled xylem formed in late summer when water is scarce.

Monocot vs. Dicot leaf venation

Monocots typically have parallel veins; dicots have branched, net-like veins.

Tendrils

Coiling structures (often modified leaves) used for support.

Spines

Modified leaves in cacti; photosynthesis often occurs in stems.

Storage leaves

Leaves modified to store water or nutrients in succulent plants.

Bracts

Modified leaves near flowers; often colorful to attract pollinators.

Reproductive leaves

Leaves that produce plantlets for asexual reproduction.

Intercalary meristem

Meristem at bases of stems and leaves in monocots; allows rapid regrowth after damage.

Rays

Wood rays; transport water, minerals, and carbohydrates horizontally within wood.

Sapwood

(Note: duplicate reference avoided in final set; kept as a distinct term here for clarity) Wood region that conducts water near the cambium.

Pith

Internal region of the stem ground tissue; located inside the vascular tissue.